Fluorocarbons and related compounds such as fluorocarbon amines and ethers have become an essential component of many `high technology` industries. The unique combination of properties such as resistance to chemical oxidation, thermal stability, low toxicity and non-flammability have assured the use of such materials in situations where a particular need is of such importance that the relatively high cost is justified.
Several types of fluorocarbon fluids have found specialized uses as coolants and insulators in high voltage equipment, immersion media for leak testing, and heat transfer agents in vapor phase soldering processes. Preparation, Properties and Industrial Applications of Organofluorine Compounds (ed. R. E. Banks) Wiley and Sons, New York, 1982. They are used as vacuum pump fluids where their chemical stability allows a very clean vacuum even where hostile chemical and physical conditions are involved. Caporiccio, G., et al., Ind. Eng. Chem. Prod. Res. Dev. 21, 515-519 (1982).
Several commercially available polyether fluids are made by the telomerization of hexafluoropropylene oxide. These materials are produced by the photo-oxidation of liquid hexafluoropropylene to yield polyperoxides, --(C.sub.3 F.sub.6 O).sub.m --(C.sub.3 F.sub.6 OO).sub.n -- which are heated to destroy the peroxide linkages. The resultant polymers are end capped by reaction with elemental fluorine. The material is then separated into various fractions by distillation. Sianesi, D., et al., Chim. Ind. (Milan) 1973, 55(2), 208-221.
Fluorocarbon polyethers have been made by several routes by direct fluorination. The direct reaction of polyethers such as poly(ethylene glycol) (Gerhardt, G. and Lagow, R. J., J. Org. Chem. 43, 4505, (1978)) poly(propylene oxide) and poly(methylene oxide) (Gerhardt, G. and Lagow, R. J., Chem. Soc. Perkin Trans. 1 1321 (1981)) gave corresponding fluorocarbon polyethers. The fluorination of copolymers of hexafluoroacetone and either ethylene oxide, propylene oxide or trimethylene oxide (Persico, D. F. and Lagow, R. J., Macromolecules 18, 1383 (1985)) yielded perfluoropolyethers with a branched structure. Finally, the action of sulfur tetrafluoride on polyesters (Persico, D. F. and Lagow, R. J., Makromol. Chem. Rapid Commun. 6, 85 (1985)) also gives fluorocarbon polyethers of various structures.